In the past, there have been different types of energy conversion methods. Many of these methods are traditional turbo-machinery-based energy conversion methods, such as exemplified by the Rankine or Brayton cycles. These energy conversion methods have encountered problems with wear of moving parts within the generator. Moving parts often become worn and require replacement.
There have been several alternatives to the more traditional turbo-machinery-based energy conversion methods. For instance, photovoltaic converters have been used to convert solar radiation directly into electrical energy. Photovoltaic converters are solar cells which convert a fraction of the incident solar radiation directly into electrical energy. Solar cells are used in a wide range of applications, from low to medium-scale systems for power generation.
Like solar cells, thermovoltaic (TV) energy conversion eliminates the use of moving parts within the generator. TV power production is based upon positioning semiconducting TV "cells" (similar to solar cells) in the photon flux field of a high temperature photon emitter. TV energy conversion has been contemplated at temperatures above 2,000.degree. F., where the photon energy spectrum is high. TV energy conversion at temperatures below 2000.degree. F. has received little attention. This lack of attention can be attributed to the lack of quality semiconducting materials which can take advantage of the relatively low energy photon spectrum emitted by a "low" temperature heat source. Recently, TV cells which are "tuned" to the lower energy, longer wavelength photon spectrum of the emitter have been fabricated. Thus, there is need in the art for a TV energy converter which can convert the photon energy in the lower energy photon spectrum into electricity.